Hyperkyphosis in older adults is an important, common problem, associated with significant disability, morbidity, and mortality, and will increase with the aging of the population. Despite the public health burden, there are no guidelines for prevention, treatment, or management even though there is increasing evidence for effective interventions to reduce progression and even improve thoracic kyphosis. A critical barrier to developing efforts to prevent and treat hyperkyphosis is a lack of information on (1) the natural history of progression of kyphosis in women and men throughout adulthood, (2) the spinal features that contribute to progression, and (3) the adverse health outcomes associated with progression of kyphosis. This project is highly significant, because the 3 aims of this study directly address this gap in knowledge. We propose to conduct a longitudinal study of 6-year change in thoracic kyphosis, or Cobb angle, in 2,000 women and men in the Framingham Study. First, we will determine the contribution of baseline age, baseline kyphosis angle, and prevalent vertebral fracture status to progression of kyphosis in women and men. Second, we will determine the contribution of declines in intervertebral disc height, declines in spinal muscle mass, progression of facet joint osteoarthritis, and incidence of vertebral fracture to progression of kyphosis in women and men. Third, we will determine the association between progression of kyphosis and declines in lung function (assessed by spirometry) and physical function (timed walk, Nagi and Rosow-Breslau scales) in women and men. This project leverages comprehensive, high quality, clinical data, previously collected in a well-characterized community-based study, to fill a critical gap in knowledge required to develop efforts to prevent and treat hyperkyphosis and avoid further adverse health outcomes. The research team represents expertise in epidemiology, biomechanics and clinical medicine necessary to investigate this significant, complex condition. Our findings have a high likelihood of significantly impacting clinical practice and public health. By identifying factors that contribute to progression of kyphosis and adverse health outcomes associated with progression of kyphosis, this study will inform efforts to identify individuals at high risk for progression and candidates for prevention, treatment, and management to avoid further disease burden.